Tractive type relay



Nov. 1, 1938. w. K. HOWE ET AL.

TRACTIVE TYPE RELAY Filed Dec. 29, 1932 2 Sheets-Sheet 1 Fuel.

w. /5. M21 13 BY MMWM f/Z' ATTORNEY Nov. 1, 1938.

W. K. HOWE ET AL TRACTIVE TYPE RELAY Filed Dec. 29, 1932 2 Sheets-Sheet 2 INVENTOR5 1),, ATTORNEY Patented Nov. 1, 1938 UNITED STATES PATENT OFFICE TRACTIVE TYPE RELAY Application December 29, 1932, Serial No. 649,368

6 Claims.

This invention relates in general to relays adapted for railway use, and has more particular reference to relays of the tractive type which have their armatures mechanically interlocked.

Among the objects of this invention is to provide the two tractive type relays, each of which has front and back contacts, with their armatures so interlocked by equalizer means that their back contacts are always opened when both relays are de-energized and the back contacts of either relay may be closed only when the other relay is energized. A further object is to provide a structure which is compact in design, rigid in construction and particularly suitable for use in railway control systems.

Other objects, purposes and characteristic features of the present invention will be in part obvious from the accompanying drawings, and in part pointed out as the description of the invention progresses.

In describing the invention in detail, reference will be made to the accompanying drawings in which similar reference characters refer to corresponding parts throughout several views, and in which- Fig. 1 is a front elevaticnal view of the complete embodiment of this invention;

Fig. 2 is a top view of the interlocking equalizers shown in Fig. 1 with certain parts removed or shown in section;

Fig. 3 is a side View of Fig. 2 with certain parts removed;

Fig. 4 is the same as Fig. 2 but with one of the two armatures in an actuated position;

Fig. 5 is the same as Fig. 2 but with the other of the two armatures in an actuated position;

Fig. 6 is the same as Fig. 2 but with both of the armatures in actuated positions; and

Fig. 7 illustrates a circuit arrangement in which a relay mechanism embodying the present invention is more particularly useful.

With reference to the accompanying drawings, the e1ectro-magnetic relay means of the present invention preferably provides two tractive type relays A and B interrelated by an equalizer E, all of which are mounted upon a vertical terminal board 5 suitably located and formed of insulating material.

With reference to Fig. 1 of the accompanying drawings, the relay A is shown as having an elec tro-magnetic structure which forms a U-shaped electro-magnet having pole pieces 6 and l which are energized by their respective coils 8 and 9. An armature H1 is vertically supported on an edge bearing ll, and is biased away from the pole pieces 6 and 1 by a coil spring l2. The armature in has mounted thereon an articulated contact 13 which suitably engages its front and back points, as hereinafter described.

The relay B is substantially identical with the relay A and is therefore provided with pole pieces l4 and !5 having associated therewith coils l6 and IT respectively. An armature I 8 associated with the pole pieces l4 and I5 is pivotally supported on an edge bearing l 9, and is biased away from the pole pieces by coil spring 20. Mounted on the armature I8 is an articulated contact finger 2! which cooperates with its front and back points, hereinafter described.

It is of course understood that the contact fingers I3 and 2! are suitably insulated from their respective armatures l and I8.

The structure of the relays A and B, as above described, may be of any suitable type and design in accordance with the usual engineering standards, but for convenience, has been illustrated as being of the type disclosed in detail in the pending application of J. F. Merkel, Ser. No. 552,906, filed July 24, 1931, and now Patent 2,G02,476, granted May 21, 1935.

The equalizer E interconnects or interrelates the armatures l!) and is, so that they cannot both assume their extreme biased positions at the same time. This equalizer structure comprises a support member 25 (see Fig. 2), which is formed of square brass stock having an extending round threaded portion 25 that suitably passes through the terminal board and receives the nut 21. The support member 25 is prevented from turning a locking member 28 which is of unsymmetrical shape and passes over the bolt portion 28. This unsymmetrical lock member 28 is located in a recess in the mounting panel 5, which recess conforms to the unsymmetrical shape of the locking member 28 to prevent its movement, while relative motion between the locking member 28 and the support member 25 is prevented by a protruding portion 29 (see Fig. 3) which engages the square corners of support member 25.

The support member 25 at its free end divides into two protruding arms 3%) and 3| between which the equalizer arms 32 and 33 are pivotally mounted upon the bolt 34 keyed in position by a cotter key 35.

The equalizer arms 32 and 33 are L-shaped, each having one of its extending arms located between the arms 39 and 3! of the support member 25 and held within the recess made by these arms 39 and 3! to a central position by bronze leaf springs 36 and 3'! which are secured upon the support member 25 by screws 38 and 39.

The opposite end of each equalizer arm 32 and engages its respective armature l0 and I8 by having hand shaped portions which clasp the respective armatures. These hand shaped portions have protruding fingers 4B and M respectively which are brought to a rounding edge on their extremities, so as to pivotally engage their respective armatures on one side; while these hand shaped portions have what may be conveniently termed thumbs 42 and 43 that are bent over to pivotally engage the opposite side of their respective armatures.

,The ends of the equalizer arms 32 and 33 which are engaged by the springs 36 and 31 are bent over so as to engage each other, as may be best seen in Figs. 2 and 3. Thus, with the bias of the armatures Ill and I8 away from their respective pole pieces, as provided by coil springs l2 and 20 respectively, the equalizer arms 2 and 33 engage each other at the protruding portions 44 and 45, so that the tensions balance each other. In other words, the arms 32 and 33 are rigid, so to speak, when forces are applied in downward directions on each arm as viewed in Fig. 2. As the tensions or forces supplied by springs l2 and 20- are substantially equal, the armatures l0 and i8 substantially balance each other. However, as a further assurance that the armatures l5 and 18 will assume balanced mid positions, the leaf springs 35 and 3'. center the arms 32 and 33 within the enclosure provided by the protruding arms 3% and 3! or" the support member 25.

When the armature E0 is actuated to a picked up position by reason of the energization of its coils 8 and 9, the equalizer arm 32 forces the spring Bl to the left, as viewed in Fig. 4. This allows the tension provided by coil spring 2? to cause the armature E8 to move downwardly, as viewed in Fig. and outwardly as viewed in Fig. 1, so that the contact 2i can connect with its back point.

When the armature i3 is released, the tension of the coil spring 12 and the centering spring 37 returns both of the armatures l0 and 53 to neutral deenergized positions, as illustrated in Figs. 1 and 2.

When the armature 48 is attracted to its pole pieces and 55 by the energization of their respective coils l5 and ii, the spring is actuated to the right, as viewed in Fig. 5. This allows the compression or tension provided by coil spring I2 to move the armature it away from its pole pieces until its contact is connects with its back point.

It is apparent that when both the aimatures 53 and i8 are attracted to their respective pole pieces, that the equalizer arms 32 and 33 separate at protruding portions 4 and 45 and respectively actuate the springs 31 and to left hand and right hand positions, as viewed in Fig. 6. In other words, the projections M and G5 do not interfere with the movement of the arms 32 and 33 when both armatures are actuated to picked up positions.

An electromagnetic relay device as constructed in accordance with the present invention has been diagrammatically illustrated in a control system for a railroad track switch in Fig. 7 of the accompanying drawings. In this Fig. 7, the relays A and B of Fig. 1 have shown only their respective coils 8-4] and E6l'l together with their respective movable contact arms 13 and 2|. These contact arms !3 and 23 are equalized through the medium of the equalizer E, (conventionally represented in this figure) as above described. The contacts l3 and Bi have front and back points which have associated therewith suitable electromagnetic blow-out means provided in coils 45 and 47. These contacts l3 and 2| serve to control the application of energy to the armature and field windings of a switch machine SM which operates a track switch TS from normal extreme locked positions to reverse extreme locked positions.

Associated with the switch machine SM and the track switch TS is a suitable point detector contact mechanism PD which has movable contacts actuated to extreme normal or reverse positions when the track switch TS is in the corresponding extreme positions and locked, but which are actuated to intermediate or mid-stroke positions whenever the track switch TS is being operated or is unlocked.

A control relay OR of the two-position polarized type such as disclosed, for example, in the pending application of J. F. Merkel, Ser. No. 536,917, filed May 12, 1931, is governed in accordance with the position of a switch machine control lever SML located in the central tower.

The opposite terminals of a suitable battery or other source of electric energy is indicated by the symbols and The actuation of the lever SML to a right or a left hand position is repeated by the control relay CR by actuating its polar contact 48 to a corresponding right or left hand position.

With the track switch TS in a normal position, and the contact 48 of relay CR in a right hand position, the relays A and B respectively are deenergized.

Assuming that the operator moves the lever SML to a reverse position which is repeated by the polar contact 48 moving to a left hand position, an energizing circuit is closed for the relay B from through a circuit including polar contact 43 in a left hand position, movable contact 49 of the point detector contact mechanism PD in a normal position, windings l6 and ll of relay B, to The energization of the relay B actuates the contact 2| to connect with its front point. The equalizer E therefore allows the contact to drop and connect with its back point. Such operation causes current to flow in the armature and field windings of the motor from through a circuit including front contact 2| of relay B, blow-out winding 47, field winding F, blow-out winding 46, back contact I3 of relay A, windings of the armature AM, to This causes the reverse operation of the track switch by first unlocking it and then operating it to a reverse position and then again looking it.

During such operation, the contacts 49 and 50 of the point detector contact mechanism PD are operated to intermediate or mid-stroke positions. Thus, the relay B continues to be energized and the energization of the relay A is made possible provided the polar contact 43 is returned to a normal position.

Upon the completion of the operating stroke of the track switch TS, the contacts 49 and 50 of the point detector contact mechanism PD are operated to extreme reverse positions and the relay B is deenergized; although the relay A is prepared for energization upon the return of the polar contact 43 to a right hand position.

The deenergization of the relay 13 causes the contact 2! to drop away to a neutral or deenergized position and causes the contact l3 of the relay 3 to be picked up to a neutral or deenergized position by reason of the equalizer E. Such operation deenergizes the armature and field windings AM and F of the switch machine motor.

It is apparent that the operation of the track switch TS to the normal position from the reverse position is merely an inverse function of the operation already described and will be readily understood by analogy thereto.

With reference to Fig. 7, it is apparent that the armature windings AM are connected only to the negative terminal of the electrical source and that the field windings F are entirely disconnected from the terminals of the source of current. With this arrangement, a cross accidentally applying positive energy to the point 80 can not cause the operation of the switch machine motor, as might be the case if the contacts l3 and 2| of the relays A and B were both assuming back point contacting positions.

It is of course impossible for the contacts [3 and 2! of the relays A and B respectively to assume back point contacting positions in accordance with the system of the present invention. However, it is convenient to assumethat such a condition exists, as is possible in various prior systems, in order to understand the problem which the present invention so adequately solves.

For example, assuming that positive energy is accidentally applied to the point 60 with both the contacts 13 and 2| making back point connections, energy flows through back point l3 through the windings of the armature AM, to This energizes the armature windings and the heavy current, which flows, causes in many cases a sufiicient potential drop between the point of the erroneous application of potential and the upper terminal of the armature AM, to cause a sufficient energization of the field winding F to result in the creeping of the motor armature, if not an actual operation. This is because of two reasons, namely, the heavy current which flows and the high resistance of back point contacts in many cases.

Thus, an electromagnetic relay means has been shown and described, which means is particularly adapted for use in railway control systems, as has been explained in detail in one typical system.

Having described a relay mechanism, its structure and operation, it is to be understood that the embodiment shown and described is merely illustrative of one specific embodiment of the invention; and it is to be understood that various modifications and adaptations for various types of systems may be made to this embodiment without departing from the spirit or scope of the invention as pointed out in the appended claims.

What we claim is:

1. In combination, two neutral relays, each having a front contact, a back contact, an ar mature, and an operating winding for the armature, each armature being operable by its winding to make up its front contact, and interlock means including an arm operated respectively by each armature, and a detent on each arm positioned in the path of travel of the detent on the other arm preventing the positioning of both armatures to make up the back points at the same time, the interlock means permitting either armature to make up its back point only if the other is making up its front point.

2. In combination, two neutral relays, each having a front contact, a back contact, an armature, and an operating winding for the armature, each armature being operable by its winding to make up its front contact, resilient means biasing the armatures to positions to make up their back points, and interlocking means including a lock arm carried by each armature, a detent on each arm, means biasing the arm to a normal position in which neither front or back points are made up, the detents in normal position each blocking the other from moving in the direction for closing a back point.

3. In combination, two neutral relays, each having a front contact, a back contact, an armature, and an operating winding for the armature, each armature being operable by its winding to make up its front contact, resilient means biasing the armatures to positions to make up their back points, and interlocking means including a lock arm carried by each armature, a detent on each arm, means biasing the arms to a normal position in which neither front or back points are made up, the detents in normal position each blocking the other from moving in the direction for closing a back point, but not blocking the other from moving in the direction for closing a front point, thus permitting either armature to make up its back point if the other is making up its front point.

4. In combination, two neutral relays, each having a pivoted armature, an operating winding, and a front and back point, bias means urging each armature to a position to make up its back point, energization of its winding moving an armature to a position to make up its front point, and an interlock between the armatures, including a lever operated by each armature, a blocking arm on each lever, each arm, when its armature is in a position intermediate back and front contact making positions, blocking such movement of the other arm as is caused by the other armature moving to back point making position and resilient means biasing each armature toward its back point position.

5. In combination, two neutral relays, each having a pivoted armature, an operating winding, and, a front and. back point, biasing means urging each armature to a position to make up its back point, energization of its winding moving an armature to a position to make up its front point, and an interlock between the armatures, including a lever operated by each armature, a blocking arm on each lever, each arm, when its armature is in a position intermediate back and front contact making positions, blocking such movement of the other arm as is caused by the other armature moving to back point making position due to the means biasing each armature toward its back point position, and elastic means for biasing the armatures to the positions corresponding to neither back or fron point being closed.

6. In combination with a track switch and a switch machine for operating the same, control means for the switch machine including, a normal control relay and a reverse control relay each having an armature and front and back contact points, a normal and a reverse operating circuit for the switch machine, each circuit including a front point of its respective relay and a back point of the other relay, means for selectively energizing the relays, and equalizing means for preventing the relays, when both are deenergized, from making up their back points, the equalizing means permitting either relay to close its back point only when the other relay is energized.

WINTI-IROP K. HOWE. JOSEPH F. MERKEL. 

